题解 | 自动贩售机1

`timescale 1ns/1ns
module seller1(
	input wire clk  ,
	input wire rst  ,
	input wire d1 ,
	input wire d2 ,
	input wire d3 ,
	
	output reg out1,
	output reg [1:0]out2
);
//*************code***********//
reg [2:0] cnt;
always@(posedge clk or negedge rst)
 if(!rst) begin
    cnt  <= 0;
	out1 <= 0;
	out2 <= 0;
 end
  else if(d1) cnt <= cnt + 1;
  else if(d2) cnt <= cnt + 2;
  else if(d3) cnt <= cnt + 4;//2=4个0.5
  else if(cnt >= 3) begin//1.5
	out1 <= 1;
	out2 <= cnt - 3;//去掉饮料钱还剩下多少个0.5，找零
	cnt  <= 0;
  end
  else begin
	out1 <= 0;
	out2 <= 0;
  end

//*************code***********//
endmodule